Automatic fire-door



(No Model.)

W. J. LANE.

AUTOMATIGPIRE DOOR.

No, 583,492; Patented June 1, 1897.

FIGLI.

FIG.2.

WIIIVESSES: J lA/VE/VTOR z WW ATTORNEY.

UNITED STATES PATENT EErcE.

WILLIAM J. LANE, OF POUGHKEEPSIE, NEXV YORK.

AUTOMATIC FIRE-DOOR.

SPECIFICATION forming part of Letters Patent No. 588,492, dated June 1, 1897.

Application filed November 25, 1896. Serial No. 613,444. (No model.)

T0 on whom it may concern:

Be it known that I,\VILLIAM J. LANE, a citizen of the United States, residing at Poughkeepsie, State of New York, have invented new and useful Improvements in Automatic Fire-Doors, of which the following is a specification.

My invention has relation to automatic firedoors and to an improved form of that type of fire-door wherein a sliding door hung so as to close by gravity is restrained under ordinary conditions from closing by a cord or chain a part of which is adapted to be destroyed under the influence of an abnormal degree of heat, so that the restraining force is removed and the tendency to close is unchecked.

Doors of the class above named have in general been open to the objection that they were so arranged that if the door were left partly closed it would shield the fusible or otherwise destructible element from flames or currents of hot air coming from that side of the door opposite to that on which said destructible element was located. The result of such an accident would be to retard the heating of the destructible element, so as in many cases to prevent closing of the fire-door until it was too late.

It is the object of my invention to provide means whereby fire-doors of the type above named may be controlled by a destructible element which cannot be shielded by the firedoor except When actually closed, or substantially so, and at the same time will not involve the use of any projection attached to the door itself, involving a practical narrowing of the available opening.

My invention is illustrated in the accompanying drawings, wherein- Figure 1 shows a view of one well-known form of door of the type above named embodying the objectionable structure my invention is intended to obviate. Fig. 2 is a view of one form of my improved door, and Fig. 3 is a detail view of a modification of one portion of the device illustrated in Fig. 2.

In the form shown in Fig. 1 the fire-door 1, made in any well-known manner suitable to prevention of the spreading of fire from one side of the opening it commands to the other, is mounted so as to automatically close when released from the restraint of the cord or chain 2, as, for instance, by means of rollers 3 on a track 4, inclined so that the door tends to close by gravity. The tension on the cord 2 is produced by a weight 5 and is so directed by means of the two pulleys 6 and 7 as to tend to hold the door open. It is usual to make the opening tendency of the weighted cord about equal to the closing tendency of the weight of the door and thus cause the door to maintain any position in which it is placed. The door can thus be opened and closed by hand and left partly opened, if de-.

sired for any reason.

At some convenient point in the cord 2 the destructible element 8 is introduced. This usually consists of a link of metal of such a nature as to be fused with comparative ease and the fusing-point is so calculated that the link will be destroyed when a dangerous degree of heat affects it. It is evident that however this destructible element is placed upon the cord there will be positions of the door at which the element in question is shielded from hot currents of air or flames passing from the opposite side of the door either by the door 1 itself or by the wall. This is due to the fact that the destructible element is made movable and advances to meet the door as the latter closes. Thus this element passes the edge of the door some time before the door is closed and is thus shielded. Hence if for any reason the door is left partly closed the usefulness of the automatic door is diminished by one-half, inasmuch as it will not become operative in case of fires on the opposite side of the opening. I overcome this objection in the manner shown in one of its embodiments in Fig. 2 of the accompanying drawings. It will be seen that thecord 2 as used in accordance with my present invention is fixed at that side of the door-opening opposite to that occupied by the sliding valve when open, and that the destructible element 8 is interposed in this cord so near to the point of attachment to the fixture that it is not shielded by the door until the same is to all intents and purposes closed. The other end. of the cord 2 extends over a pin or hook 9, preferably situated quite near to the vertical line through the pulley 7, and then forms a bight, in which I hang a movable pulley 10, supporting the usual weight 5, the other end of the bight returning upward to pass over the pulley 7 and be attached to the door in the usual way, as shown. One advantage of this invention is that the door may have a wider opening in proportion to the fall of the weight 5, as said weight when attached to a movable pulley only travels one-half as far as the door.

The operation of this form of door is obvious. The destruction of the element 8 by an abnormal degree of heat causes the weight 5 to fall, and the door is thus released and allowed to close by gravity. It will be seen that the whole space under the rope or chain 2 is clear, the width of the door-space not being interfered with by any projection from the door-valve 1.

Where it is necessary to use the entire height of the door-opening, the form of attachment shown in Fig. 3 is appropriate. Here the fixed end of the cord is attached in the same manner as in Fig. 2, but it is made to avoid crossing the door-opening by pass ing around two supplemental hooks or pins 11 and 12 before being carried to the pin 9,

which in this instance is preferably placed higher relatively to the door than is shown in Fig. 2. Inasmuch as no part of the cord between the hook or pin 9 and the door-opening is intended to move in the normal use of the door the friction caused by the passage of the cord over these various pins or hooks is immaterial.

What I claim is In an automatic fire-door, a sliding valve hung so as to tend to close by gravity, a mov- 

